Cellular communication devices use various network radio access technologies to communicate wirelessly with geographically distributed base stations. Long-Term Evolution (LTE) is an example of a widely implemented radio access technology, which is used in 4th Generation (4G) communication systems. New Radio (NR) is a newer radio access technology that is used in 5th Generation (5G) communication systems. Standards for LTE and NR radio access technologies have been developed by the 3rd Generation Partnership Project (3GPP) for use by wireless communication carriers within cellular communication networks.
A communication protocol defined by the 3GPP, referred to as Non-Standalone (NSA), specifies the simultaneous use of LTE and NR for communications between a mobile device and a communications network. Specifically, NSA uses Dual Connectivity (DC), in which a user equipment (UE) uses both an LTE carrier and an NR carrier for uplink transmissions to corresponding 4G and 5G base stations. The LTE carrier is used for control-plane messaging and for user-plane communications. The NR carrier is used for additional user-plane bandwidth. In a scenario such as this, the LTE carrier is said to “anchor” the communication session.